Carbon Dioxide is Transported in the Blood Mainly _______

Question

Carbon dioxide is transported in the blood mainly _______.
A) as bicarbonate ions
B) dissolved in the plasma
C) attached to hemoglobin
D) as carbonic acid

Accepted Answer

The majority of carbon dioxide in the blood is transported as bicarbonate ions, which are formed from the reaction of carbon dioxide with water in the presence of the enzyme carbonic anhydrase. Only a small amount of carbon dioxide is carried dissolved in the plasma or attached to hemoglobin. Carbonic acid is the intermediate product of the reaction that forms bicarbonate ions.